Connector

ABSTRACT

A connector with a first substantially cylindrical section having a cavity with a spring-loaded ball-snap element comprising a ball and a spring. An at least partially conically shaped section connecting the first substantially cylindrical section and a second substantially cylindrical section. The first and the second substantially cylindrical sections and the at least partially conically section define a longitudinal length extension. The first substantially cylindrical section and the second substantially cylindrical section are off-center with respect to the longitudinal length extension. A head having a hollow portion is dimensioned to receive the second substantially cylindrical section, the at least partially conically shaped section and a part of the first substantially cylindrical section. The hollow portion has an inner wall with a circular recess dimensioned to receive the ball, removably attaching the head to the second substantially cylindrical section.

FIELD OF THE INVENTION

The present disclosure is concerned with a connector and a head, thehead being repeatedly attachable to and detachable from a handle via theconnector.

BACKGROUND OF THE INVENTION

Heads and handles for oral care implements, like manual toothbrushes,are well known in the art. Generally, tufts of bristles or othercleaning elements for cleaning teeth and soft tissue in the mouth areattached to a bristle carrier or mounting surface of the brush headintended for insertion into a user's oral cavity. The handle is usuallyattached to the head, which handle is held by a user during brushing.Usually, heads of manual toothbrushes are permanently connected to thehandle, e.g. by injection molding the bristle carrier, the handle, aneck connecting the head and the handle, in one injection molding step.After the usual lifetime of a toothbrush, i.e. after about three monthsof usage, the toothbrush is discarded. In order to provideenvironmentally friendly/sustainable manual toothbrushes generating lesswaste when the brushes are discarded, manual toothbrushes are knowncomprising heads or head refills being exchangeable, i.e. repeatedlyattachable to and detachable from the handle. Instead of buying acompletely new toothbrush, consumers can re-use the handle and buy a newhead refill only. Such refills are usually less expensive and generateless waste than a conventional manual toothbrush.

For example, manual toothbrushes are known comprising a handle to whicha replaceable head is connected. The handle is provided with a cavitywithin which the head is insertable. To provide sufficiently strongconnection between the head and the handle, the brush head is formedwith a neck having a coupling anchor with a number of recesses forengaging in a complementary engaging mechanism within a collar of thehandle.

However, such anchor/engaging mechanism has a relatively complex outergeometry which is not easy to clean after usage of the toothbrush.Toothpaste and slurry may accumulate in recesses of the anchor/engagingmechanism and may prevent the brush head to be accurately attachable tothe handle. Further, such handle and head construction is not easy tomanufacture in a cost-efficient manner.

Further, connector solutions featuring small plastic hooks that interactwith respective apertures are known. However, these plastic hooks relaxover time and the user needs to actively push back the hooks in parallelto pulling the refill in order to remove the brush head from the handle.Such connector solution is neither intuitive nor consumer friendly.Furthermore, such connectors are not easy to clean. Moreover, engagingparts provided in the brush refill are necessary which results inadditional manufacturing costs and complexity.

It is an object of the present disclosure to provide a method formanufacturing an oral care implement in a cost-efficient and easymanner, in particular a method for manufacturing a manual toothbrushcomprising a handle and a head, the head being repeatedly attachable toand detachable from the handle.

SUMMARY OF THE INVENTION

In accordance with one aspect a method for manufacturing an oral careimplement is provided, the implement comprising a handle, a connectorand a head, the head being repeatedly attachable to and detachable fromthe handle via the connector, the method comprising the following steps:

-   -   injection molding of at least a part of the handle, the handle        having a distal end and a proximal end being opposite the distal        end, the proximal end comprising a hollow portion;    -   injection molding of at least a part of the connector, the        connector having an outer lateral surface and a recess therein,        the recess forming a cavity within the connector,    -   injection molding of at least a part of the head,    -   inserting the connector into in the hollow portion of the        handle, and fixing the connector, preferably by gluing, welding        and/or press-fitting.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in more detail below with reference tovarious embodiments and figures, wherein:

FIG. 1 shows a perspective view of an example embodiment of a manualoral care implement according to the present disclosure, the oral careimplement comprising a head, a handle and a connector;

FIG. 2 shows a perspective view of the handle with connector of FIG. 1 ;

FIG. 3 shows a schematic side view of the handle with connectoraccording to FIG. 2 ;

FIG. 4 shows a schematic front view of the handle with connectoraccording to FIG. 2 ;

FIG. 5 shows a schematic top-down view of the handle with connectoraccording to FIG. 2 ;

FIG. 6 shows a front view of an example embodiment of a connectoraccording to the present disclosure;

FIG. 7 shows a side view of the connector of FIG. 6 ;

FIG. 8 shows a longitudinal cross-sectional view of the handle withconnector of FIG. 2 ;

FIG. 9 shows the cross-sectional view along line A-A;

FIG. 10 shows the cross-sectional view along line B-B;

FIG. 11 shows a schematic perspective view of the head of the manualoral care implement of FIG. 1 ;

FIG. 12 shows a bottom view of the head of FIG. 11 ; and

FIG. 13 shows a flow chart for manufacturing the handle comprising theconnector of the oral care implement of FIG. 1 ; and

FIG. 14 is a graph showing average results of heat transfer and flowdistance.

DETAILED DESCRIPTION OF THE INVENTION

The method for manufacturing an oral care implement according to thepresent disclosure comprises the following steps:

-   -   injection molding of at least a part of the handle, the handle        having a distal end and a proximal end being opposite the distal        end, the proximal end comprising a hollow portion;    -   injection molding of at least a part of the connector, the        connector having an outer lateral surface and a recess therein,        the recess forming a cavity within the connector,    -   injection molding of at least a part of the head,    -   inserting the connector into in the hollow portion of the        handle, and fixing the connector, preferably by gluing, welding        and/or press-fitting.

The oral care implement comprises a handle and a head on which at leastone tooth and/or tissues cleaning element, e.g. a tuft of bristlesand/or an elastomeric element, is fixed. The head is repeatedlyattachable to and detachable from the handle. The oral care implementmay be a manual toothbrush, or alternatively an inter-proximal pick, aplaque scraper or tissue/tongue cleanser. As the connector is fixed inand forms a part of the handle, the connector—representing a relativelyexpensive part of the overall oral care implement—can be used over anextended/longer period of time. The head—having a relatively simplestructure and being relatively cheap as compared to the handlecomprising the connector—can be replaced after usual time of usage, e.g.every three months. A new head refill can be purchased at relatively lowcosts. While replaceable brush heads according to the state of the artconsist out of an assembly of multiple parts or comprise at least oneadditional insert, the frequently exchangeable brush heads for the oralcare implement according to the present disclosure can be produced atlower costs.

The method step for manufacturing the handle of the oral care implementmay comprise:

-   -   providing an amorphous thermoplastic resin,    -   providing aluminum oxide, boron nitride or aluminum silicate,    -   providing iron oxide,    -   mixing the amorphous thermoplastic resin, aluminum oxide, boron        nitride or aluminum silicate and iron oxide into a magnetic        and/or ferromagnetic molding material,    -   heating the molding material mixture into a flowable molding        material, and    -   molding the flowable molding mixture into a handle or part of a        handle.

The amorphous thermoplastic resin may comprise styrene acrylonitrile,polybutylene terephthalate and polyethylene terephthalate, whereinpolybutylene terephthalate and polyethylene terephthalate may bepremixed with glass fibers. The amorphous thermoplastic resin may beprovided in a range from about 13 weight percent to about 30 weightpercent; the aluminum oxide, boron nitride or aluminum silicate may beprovided in a range from about 3 weight percent to about 25 weightpercent; and the iron oxide may be provided in a range from about 45weight percent to about 67 weight percent.

The magnetic and/or ferromagnetic material may comprise about 17 weightpercent of styrene acrylonitrile; about 10.5 weight percent of acomposition comprising polybutylene terephthalate and polyethyleneterephthalate; about 4.5 weight percent of glass fibers; about 17 weightpercent of aluminum oxide; and about 51 weight percent of iron oxide.

The material composition may be made by blending the amorphousthermoplastic resin with powder of aluminum oxide, boron nitride oraluminum silicate, and with iron oxide powder. Increasing the amount ofiron oxide within the material composition has further the advantage ofproviding a lower cost molding material because iron oxide powder isless expensive than the other filling agents. Amorphous thermoplasticresin, glass fibers, aluminum oxide/boron nitride or aluminum silicatepowder, and iron oxide powder may be blended by using a uniaxialextruder, a biaxial extruder, a kneader, a Banbury mixer, a roll orother such extruders. After blending, the material is heated to becomeflowable. The flowable material may then be molded into a handle or partof a handle by injection molding.

The method for manufacturing the oral care implement may furthercomprise the following steps:

-   -   providing a spring-loaded ball-snap element, the element        comprising a ball and a spring, the spring applying a radial        force onto the ball,    -   inserting the spring-loaded ball-snap element into the cavity of        the connector and fixing the connector, preferably by a        press-fitting process, so that the spring applies a radial force        onto the ball in a direction towards the outer lateral surface        of the connector.

By providing a spring-loaded ball-snap element in the connector, thehead of the oral care implement is attachable to the handle via asnap-fit locking mechanism to ensure sufficiently strong connection andstability between the head and the handle. The spring-loaded ball-snapelement comprises a ball and a spring, the spring applying a radialforce onto the ball in a direction towards the outer lateral surface ofthe connector. In the following a radial force is defined by a forceapplied in a direction being substantially perpendicular to thelongitudinal length extension of the connector. In other words, thespring applies a force onto the ball and pushes the ball outwards sothat the ball extends slightly beyond the outer lateral surface of theconnector. The ball may engage with a recess provided in a hollowportion of the head when the head gets attached to the handle. Once thehead is snap-fitted onto the connector, the head is fixed on thehandle/connector in an axial direction. In other words, the connectorand the oral care implement comprising such connector, respectively,allow for easy attachment/detachment of the head to and from the handle.The user can attach the brush head to the handle by a simple linearmotion. Further, the ball-snap provides a precise fixation of the brushhead, and a distinct haptic feedback is given to the user that the headis snapped-on securely. In other words, the user recognizes once theball engages into the recess provided in the inner wall of the hollowportion of the head. The brush head can be easily removed, i.e. withoutperforming a synchronized action with other elements/unlockingmechanisms.

The head may be fixed on the handle until a specific/predeterminedpull-off force is applied. The connection between the head and connectoris sufficiently strong enabling well-coordinated brushing techniques.The head may not get loosened from the handle and may not twist asideduring brushing.

The ball and/or the spring of the spring-loaded ball element may be madefrom stainless steel. While typical snap elements comprise a springelement made from plastic that shows relaxation and aging effects overtime, a stainless steel spring shows a constant spring rate over time,also under extended use conditions (e.g. temperature). A spring-loadedball element made from stainless steel may provide long-lasting,reliable fixation of the head on the connector/handle. Moreover, if thespring-loaded ball snap element is made completely from stainless steel,an electrical contact from the handle to the refill can be easilyprovided. In order to provide a closed electric circuit, an electricalconductive ring at the proximal end of the handle can be attached as asecond contact. An electrical contact from the handle to the refillallows for various additional functions, e.g. light for diagnostics ortreatment, e.g. for iontophoresis.

The spring-loaded ball element may be fixed in the cavity by apress-fitting process, welding and/or gluing which represents an easyand cost-efficient method.

In an additional step, the handle or part of the handle may beelectroplated to add improved appearance and a pleasant feel. Forexample, by an electroplating step, the handle, or a part of the handlemay be provided with a metal layer or coating, e.g. made from chrome,silver or gold to further improve the appearance of the handle.

Thermoplastic elastomers are also well suited for electroplating as theyallow for the creation of both, hard and soft composite components to beelectroplated selectively in one operation. Therefore, in addition, oralternatively, the handle may be electroplated with any additionalmaterial, for example a polyethylene material or a thermoplasticelastomer to create a soft region, e.g. a thumb rest. The softregion/thumb rest may improve the comfort and feel of the handle. Suchthumb rest may provide the handle of the oral care implement withimproved handling properties, e.g. with anti-slip properties to improvethe maneuverability of the oral care implement under wet conditions,e.g. when the user brushes his teeth. The thumb rest may be made fromthermoplastic elastomer having a Shore A hardness from about 30 to about60, or about 40 to prevent the oral care implement from being tooslippery when used in wet conditions. At least a portion of the thumbrest may have a concave shape with an angle α with respect to the areaof the remaining portion of the thumb rest from about 20° to about 25°,or about 24°. The thumb rest or a gripping region may be attached ontothe front surface of the handle in the region close to the proximal end,i.e. closest to the head. The thumb rest may comprise a plurality ofribs extending substantially perpendicular to the longitudinal axis ofthe oral care implement. Such ribs may allow users/consumers to use theoral care implement with even more control. The user/consumer can bettergrasp and manipulate the handle of the oral care implement duringbrushing. Such handle may provide further improved control and greatercomfort during brushing, in particular under wet conditions.

The handle may be made from at least two, or at least three differentmaterials, each forming different parts of the handle. For example, afirst material, e.g. a magnetic and/or ferromagnetic material may beinjection molded into a first component of the handle thereby forming anunderlying base structure of the oral care implement. A secondcomponent, e.g. of polypropylene material may be injection molded overthe first component, and/or a third component, e.g. of thermoplasticelastomer material may be injection molded over the first componentand/or the second component.

The third component of thermoplastic elastomer material may form a thumbrest on the front surface of the oral care implement and/or a palm gripon the back surface being opposite the front surface to be gripped bythe user's/consumer's fingers and thumb. Such handle configuration mayeven further resist slippage during use. The thermoplastic elastomermaterial may extend through an aperture provided in the underlying basestructure and/or second component of the handle.

The method for manufacturing the oral care implement may furthercomprises the following steps:

-   -   providing a ring,    -   attaching the ring onto the proximal end of the handle,        preferably by gluing, welding and/or press-fitting. For example,        the ring may be a metal layer surrounding the outer        circumference of the handle. Such ring may serve as        identification means.

The handle may be injection molded in a manner so that the proximal endof the handle has an upper surface being at least partially chamfered,and the chamfered upper surface and a cross-sectional area extendingsubstantially perpendicular to the longitudinal axis of the handledefine an angle α from about 15° to about 30°, or from about 18° toabout 28°, or about 25°. Surprisingly, it has been found out that suchangled/chamfered surface provides an anti-twist protection duringbrushing. In other words, if lateral forces are applied onto the brushhead during brushing, the head may not easily twist aside. Furthermore,the angled/chamfered surface allows for draining-off fluids, liketoothpaste slurry and saliva, after use of the oral care implement,thereby preventing accumulation of such fluids over time. The overalloral care implement can be kept clean over an extended period of timewhich renders the implement more hygienic.

Corresponding to the handle, the head may be manufactured and formed ina way that a proximal end of the head being opposite a distal end andclosest to the handle when the head is attached thereto, has an uppersurface which is chamfered, as well. The chamfered upper surface and thecross-sectional area of the head which is substantially perpendicular tothe longitudinal axis of the head may define an angle β from about 15°to about 30°, or from about 18° to about 28°, or about 25°. Suchconfiguration may allow for precise adjusting and fitting of the headonto the handle. The user can attach the head to the handle by a simplelinear motion. With the chamfered surface of the handle and thecorresponding chamfered surface of the head, the head is turned into theright orientation automatically during the attachment motion.

The connector may be injection molded in a manner so that at least afirst substantially cylindrical section, a second substantiallycylindrical section, and an at least partially conically shaped sectionconnecting the first and the second cylindrical sections are formed, thefirst substantially cylindrical section, the at least partiallyconically shaped section and the second substantially cylindricalsection are arranged in consecutive order along a longitudinal lengthextension, and the first substantially cylindrical section and thesecond substantially cylindrical section are placed off-center withrespect to the longitudinal length extension.

In the following, a substantially cylindrical section is defined by athree-dimensional body having a longitudinal length extension and across-sectional area extending substantially perpendicular to thelongitudinal length extension. The cross-sectional area has a shapebeing substantially constant along the longitudinal length extension.Since the connector may be manufactured by an injection molding process,a substantially cylindrical section also comprises sections/bodies whichhave a slight draft angle of up to 2°, or up to 1°. In other words, asubstantially cylindrical section also comprises a section/body whichtapers slightly by up to 2°, or up to 1° towards a proximal end which isclosest to the head once the head is attached to the connector.

The cross-sectional area may have any shape, for example substantiallycircular, ellipsoid, rectangular, semi-circular, circular with aflattening portion, convex or concave. The cross-sectional area may havethe shape of a polygon, for example of a square or triangle. The outerlateral surface circumventing the cylinder along its length extensioncan be defined as being composed of straight lines which aresubstantially parallel with respect to the longitudinal length extensionof the cylinder.

The proximal end of the head may comprise a hollow portion for receivinga part of the connector, for example, the second substantiallycylindrical section, the at least partially conically shaped section anda part of the first substantially cylindrical section. The hollowportion of the head may be formed with an inner wall having ageometry/contour which corresponds to the outer geometry/contour of thepart of the connector to be inserted into the hollow portion of thehead. The eccentric arrangement/off-center positioning of thesubstantially cylindrical sections of the connector enables precisepositioning of the brush head on the handle. The geometric position ofthe head can be clearly defined. As the handle comprises the connectorat a proximal end being closest to the head, the eccentric/off-centerarrangement of the two substantially cylindrical sections may act as aguidance element when a user attaches the head to the handle. In otherwords, the two substantially cylindrical sections may allow for accuratefitting between the head and the handle. Further, theeccentric/off-center arrangement of the two substantially cylindricalsections may provide an anti-twist protection for the head on the handleduring brushing, for example if a lateral force is applied onto thehead.

The first substantially cylindrical section and the second substantiallycylindrical section may be formed with a length extension and across-sectional area extending substantially perpendicular to the lengthextension, and the cross-sectional area of the first substantiallycylindrical section and/or second of the second substantiallycylindrical section may be substantially circular. Such geometryprovides a robust and simple structure which is easy to clean afterusage of the oral care implement. Further, since the outer geometry isrelatively simple, such connector can be manufactured in acost-efficient manner.

The first substantially cylindrical section may be formed with across-sectional area being greater than the cross-sectional area of thesecond substantially cylindrical section. For example, the firstsubstantially cylindrical section to be inserted into a hollow portionat the proximal end of the handle, may have a substantially circularcross-sectional area with a diameter of about 8 mm to about 10 mm,preferably about 9 mm, while the second substantially cylindricalsection to be inserted into a hollow portion at the proximal end of thehead, may have a substantially circular cross-sectional area with adiameter of about 4 mm to about 6 mm, preferably about 5 mm.

The first and the second substantially cylindrical sections may have afirst and a second longitudinal central axis, respectively which aredefined as the symmetry axis of the first and the second substantiallycylindrical sections. The first and the second substantially cylindricalsections may be formed with respect to each other so that the secondlongitudinal central axis of the second cylindrical section is locatedoff-center with respect to the first longitudinal central axis of thefirst cylindrical section by about 1 mm to about 2.5 mm, or by about 1.5mm to about 2 mm, or by about 1.65 mm Such connector may be easy tomanufacture by injection molding, and provides sufficient torsionalstability for the oral care implement if lateral forces are applied ontothe brush head.

The first and/or the second substantially cylindrical section may beformed with a flattening portion extending along the length extension ofthe first and/or second substantially cylindrical section. Suchflattening portion may provide the toothbrush with additional anti-twistprotection for the head being connected to the handle during brushing,for example if a lateral force is applied onto the head.

The first and the second substantially cylindrical sections have a firstand a second outer surface, respectively, and the first and the secondsubstantially cylindrical sections may be formed with respect to eachother so that a part of the first outer surface and a part the secondouter surfaces are substantially in straight alignment. The flatteningportion, optionally comprising the spring-loaded ball element, may bearranged opposite the first and second outer surfaces beingsubstantially in straight alignment. Such connector has an easy to cleanouter geometry. The connector is robust, easy to use, and can bemanufactured in a cost-efficient manner.

The connector and the oral care implement comprising such connector,respectively, allow for easy attachment/detachment of the head to andfrom the handle. The user can attach the head to the handle by a simplelinear motion. With the specific design of the substantially cylindricalsections being formed off-center, and the chamfered surface of thehandle, the head is turned into the right orientation automaticallyduring the attachment motion (within certain tolerances). Therefore, theconsumer is not forced to precisely position the head on the handlebefore snapping it on. Further, the ball-snap provides a precisefixation of the brush head, and a distinct haptic feedback is given tothe consumer that the head is snapped-on securely. The brush head can beeasily removed, without any synchronized action with other elements(unlocking mechanisms). In addition, the connector can be cleanedeasily. The specific design of the connector may not have any recessesin which dirt, toothpaste and/or saliva accumulate. The connector mayalso avoid any fragile structures by comprising substantially roundedges, only, which may prevent easy breakage or damage of the surfaces.

To allow sufficiently good fitting of the brush head on the connector ifproduction tolerances occur, the inner wall of the hollow portion of thehead may be formed with at least one ribs, or two ribs being oppositeeach other, for precisely adjusting the head on the connector/handle.Furthermore, the at least one ribs may prevent compression of air in thehollow portion of the head which could act like a spring or asadditional resistance while snapping the head on the connector/handle.

At least a portion of the head, e. g. the neck/shaft and the bristlecarrier may be at least partially made from a material having a densityfrom about 0.5 g/cm³ to about 1.2 g/cm³, or from about 0.7 g/cm³ toabout 1.0 g/cm³, or about 0.9 g/cm³. For example, the head may beinjection molded from a thermoplastic polymer, e.g. polypropylene havinga density of about 0.9 g/cm³. In contrast to the head, the handle may beat least partially made from a material having a significant higherdensity, i.e. a density from about 2.1 g/cm³ to about 3.1 g/cm³, or fromabout 2.3 g/cm³ to about 2.8 g/cm³, or from about 2.5 g/cm³ to about 2.7g/cm³.

The weight of the handle material may be relatively high, to provide auser with high-quality perception and comfortable feeling during use ofthe oral care implement. Usually users are accustomed that products, inparticular in the personal health care sector, have a specific weightthat guarantees high product quality and provides comfortable feelingduring use of the product. Consequently, such oral care implementprovides such superior product quality perception.

Further, since the material of the handle may have a higher density thanthe material of the head, the center of mass/center of gravity lieswithin the handle (even if the brush head is loaded with toothpaste)which enables users to perform a well-coordinated brushing techniquewith improved sensory feeling during brushing. The center of gravityprovided in the center of the handle may provide an oral care implementwhich is better balanced and does not tip over/does not get head loadedonce toothpaste is applied onto the brush head. When users applydifferent grip styles/brushing techniques, the oral care implementaccording to the present disclosure has the advantage that the center ofgravity is in or very close to the pivot point of the wrist joint. Abalanced toothbrush is easier to control in the mouth, thereby allowingmore precise and accurate brushing movements which enables bettercleaning.

While the high quality and relatively expensive handle of the oral careimplement may be adapted for use over a longer period of time ascompared to common manual toothbrushes which are discarded after aboutthree months of use, the relatively cheap brush refill can be exchangedon a regular basis, e.g. after about three months. This provides acost-efficient and environmentally sustainable high quality oral careimplement with improved handling properties.

In the past, it has been seen that after use of the brush/after brushingthe teeth the user usually stores the wet brush in a toothbrush beakerfor drying. However, in a classical toothbrush beaker, drained fluidsget collected and accumulated at the bottom of the beaker, and, thefluids stay in contact with the toothbrush for a longer period of time.Since the beaker is open on one side only, the toothbrush driesrelatively slowly. Bacteria living in wet conditions/in a wetenvironment can grow quickly, contaminate the toothbrush and finallyrender the brush unhygienic. Consequently, there exists a need for asolution for hygienically storing and drying a manual toothbrush,thereby enabling remaining water, toothpaste slurry and saliva to drainoff from the brush. The brush shall dry quickly thereby inhibitingbacterial growth.

The material of the head may be made of a non-magnetic ornon-ferromagnetic material, while the material of the handle may be madefrom a magnetic and/or ferromagnetic material. Magnetic/ferromagneticmaterial possesses not only a relatively high density, and, thus, arelatively heavy weight, which may provide the oral care implement withthe above-mentioned benefits, but the magnetic/ferromagnetic materialalso enables the oral care implement to be magnetically attachable to amagnetic holder. The magnetic/ferromagnetic material of the handle mayallow for hygienic storage of the oral care implement. If the oral careimplement is magnetically attached to a magnetic holder, remainingwater, toothpaste slurry and saliva can drain off from the brush. Theoral care implement can dry relatively quickly. Consequently, bacteriagrowth can significantly be reduced, thereby rendering the oral careimplement more hygienic. In contrast to a common toothbrush being storedin a toothbrush beaker where drained fluids get collected andaccumulated at the bottom of the beaker, the brush according to thepresent disclosure is exposed to wet conditions over a significantlyshorter period of time.

For example, the magnetic holder may have the form of a flat diskattachable to a wall. Such flat disk may represent an easy to cleansurface. Further, a user just needs to bring the oral care implement inclose proximity to the magnetic holder, and then the oral care implementgets attached automatically. No precise positioning or threading as incommon toothbrush holder is required. Since the magnetic properties aremerely provided in the handle, and not in the head, the head portioncannot accidentally be attached to the magnetic holder, thereby reducingthe risk that the magnetic holder gets soiled.

The magnetic and/or ferromagnetic material forming at least a part ofthe handle may comprise an amorphous thermoplastic resin. The magneticand/or ferromagnetic material may further comprise aluminum oxide, boronnitride or aluminum silicate. Furthermore, the magnetic and/orferromagnetic material may comprise in addition or alternatively ironoxide. The magnetic and/or ferromagnetic material may further compriseglass fibers which may be pre-mixed with at least a portion of theamorphous thermoplastic resin. Such handle material allows for controlof the weight of the handle in whatever location, e.g. by fillervariation. Control of the overall toothbrush is required due to therelatively high weight of the handle. It is now possible to use themass/weight distribution of the material for adaption of the inertialmoment of the finished toothbrush.

The magnetic and/or ferromagnetic material may comprise from about 13weight percent to about 30 weight percent of an amorphous thermoplasticresin; from about 3 weight percent to about 25 weight percent ofaluminum oxide, boron nitride or aluminum silicate; and from about 45weight percent to about 67 weight percent of iron oxide. Suchcomposition provides a material density that is about three times thedensity of a standard plastic material used for toothbrushes, e.g.polypropylene. With higher weight and higher thermal conductivity, thematerial drives value perception, in particular in combination with agalvanic coating. Such coating may be made from real metal. The galvaniccoating can be applied in a selective electroplating process. Duringthis coating process for a multicomponent plastic part, a metallic layeris only deposited on a hard material while a further over molded softcomponent may remain unaffected.

The magnetic and/or ferromagnetic material may comprise about 27.5weight percent of an amorphous thermoplastic resin, about 17 weightpercent of aluminum oxide, about 51 weight percent of iron oxide, andabout 4.5% glass fiber.

The amorphous thermoplastic resin may comprise a styrene resin, e.g.styrene acrylonitrile “SAN”. The amorphous thermoplastic resin may beselected from the list consisting of acrylonitrile butadiene styrene,polystyrene, and styrene acrylonitrile.

The amorphous thermoplastic resin may comprise about 17% weight percentstyrene acrylonitrile, and 10.5 weight percent of a mixture comprisingpolybutylene terephthalate and polyethylene terephthalate.

Surprisingly, it has been found out that said composition provides ahigh gravity molding material appropriate for injection molding orextrusion molding. A high specific gravity molding material high insurface hardness, excellent in coating characteristics as well asexcellent in thermal conductivity is provided.

The use of molding materials having a relatively high specific gravityis known. Such molding materials usually contain a polymeric resin and ahigh-density filler such as iron oxide. However, in such moldingmaterials the amount of iron oxide which can be included is limited asthe thermal conductivity properties of the molding material arerelatively poor. Thus, on the one side, lower thermal conductivity leadsto relatively longer cycle times during manufacturing to allow themolding material to cool after molding. On the other side, if heavypolymeric materials are filled with high heat conductive additives suchas metal powder or fibers, the addition of these materials leads totight process windows in molding because of the immediate freezing whenthe molten material contacts the cold wall of the tool. This fastfreezing leads to high injection speed and low flow length to wallthickness ratio at the produced part.

Now, it has been surprisingly found out that the molding materialaccording to the present disclosure has a high specific gravity andoptimally controlled thermal conductivity properties to reduce or expandthe time needed for the molding material to cool during or afterinjection molding. Surprisingly, it has been found out that a relativelyhigh percentage of iron oxide can be maintained in the molding materialwhile improving on the thermal conductivity properties of the moldingmaterial. The addition of aluminum oxide, boron nitride or aluminumsilicate provides the molding material with improved thermalconductivity as compared to materials containing a styrene resin andiron oxide only. This improved thermal conductivity may lead to lowercycle times as the molding material needs less time to cool aftermolding.

Another benefit of adding aluminum oxide, boron nitride or aluminumsilicate to the material is the ability to increase the overall amountof iron oxide in the molding material as compared with materialscomprising iron oxide and resins of the past. The improvements in themolding material properties come from the addition of relatively smallamounts of aluminum oxide, boron nitride or aluminum silicate. Amaterial composition comprising a relatively high percentage of ironoxide (magnetite), i.e. from about 45 weight percent to about 67 weightpercent, preferably about 51 weight percent, provides good magneticproperties and a relatively heavy weight of the overall material.

Styrene acrylonitrile “SAN” provides high thermal resistance properties.The acrylonitrile units in the chain enable SAN to have a glasstransition temperature greater than 100° C. The properties of SAN mayallow for reduced cycle time due to relatively earlier and quickertransition temperature. Amorphous polymers are suitable for heavy resincompounds of the present disclosure due to the glass transitiontemperature Tg at which an amorphous polymer is transformed, in areversible way, from a viscous or rubbery condition to a hard one. Byinjection molding of the heavy resin material of the present disclosurethe temperature of the material melt is above the Tg region (viscous orrubbery condition). During cooling the compound attains the high Tgtemperature early and reaches dimensional stability (glassy condition).Over-molding of the heavy resin material is possible as the materialstays dimensional stable due to the high Tg of the material.

Polybutylene terephthalate (PBT) and/or polyethylene terephthalate (PET)provide the handle with high quality surface properties, includingimproved optical characteristics, and high impact strength. Once heated,a mixture of PBT and PET represent a high temperature-resistant melthaving low viscosity and a high Melt Flow Index (MFI). Therefore,processability of the magnetic/ferromagnetic material during molding isimproved.

It is known, that heavy resin materials tend to show high shrinkageeffects for products having thick walls/dimensions. However, it has beensurprisingly found out that glass fibers added to themagentic/ferromagentic material provide the material composition withimproved stability and low shrinkage effects.

The material according to the present disclosure is an alternative tometal/zinc-die-cast material. The material of the disclosure enables tooffer an attractive solution with respect to the manufacturing processaccording to the present disclosure, price and environment. Thisalternative allows the handle to have the look and feel in the finalstate like a metal product. At the same time the material of the presentdisclosure should be easily processable by injection molding and shouldsave on the assembly effort. For example, for the process of the presentdisclosure there are three basic steps required: (1) injection moldingof the handle 12; (2) two-component injection molding of hard materialand/or soft material, e.g. to form a thumb rest; and (3) electroplatingof the handle, e.g. to form a metal layer in the form of a ring 18. Incontrast, when using a zinc-die-cast material five steps are needed: (1)manufacturing of the zinc-die-casted main part; (2) deflashing of themain part; (3) electroplating the main part; (4) separately producing asoft material part; (5) and assembling the main part with the separatelyproduced soft material part. A lubricant may be added to the material toimprove the molding processing fluidity.

Table 1 shows the flowability and heat transfer results of severaldifferent formulas/material compositions:

TABLE 1 Flowability and heat transfer 20% SAN 15% SAN 17% SAN 20% SAN 5%Aluminum oxide 10% Aluminum oxide 16% Aluminum oxide Test-No. 80% Ironoxide 75% Iron oxide 75% Iron oxide 67% Iron oxide Specific weight 2.912.95 2.99 3.06 [g/cm³] 1 21 16 13 9 2 20 16 13 9 3 20 16 13 10 4 21 1613 9 5 20 16 14 9 6 20 16 13 8 7 20 16 13 9 8 20 16 13 9 9 20 16 13 910  20 16 13 9 Average (cm) 20.2 16 13.1 9 Content Al—Ox 0 5 10 16 [%]Heat transfer rate 0.87 0.96 1.2 1.43 [W/m * K] 0.89 1.06 1.22 1.41 0.881.01 1.23 1.44 Average Value 0.88 1.01 1.21666667 1.42666667 [W/m * K]

Graph 1, shown in FIG. 4 , plots the average results of heat transferand flow distance of the formulas from Table 1.

As can be seen, different fillers and different concentrations offillers control the thermal conductivity or heat transmission andflowability of the material.

Test results revealed that the use of boron nitride or aluminum silicateshowed very similar results to that of aluminum oxide depicted in Table1 and Graph 1 above.

The heat energy and shear heating affect the fluidity of the heavy resinmaterial, and thereby the process window for an effective injectionmolding process can be exactly controlled. Further, with the ability ofthe material of the present disclosure to fill any available cavitieswithin the mold, it is possible to use the mass/weight distribution ofthe material for adaption of the inertial moment of the finished handle.

There are several advantages related to the material of the presentdisclosure: The handle manufactured with the material of the presentdisclosure looks and feels like a heavy metal handle and it is resistantto corrosion. The material also has manufacturing advantages and costsaving advantages with fast cycle times due to its heat transferproperties as compared to metal inserted or die-casted handles andproducts with assembled component parts. The material of the presentdisclosure requires less energy and other essential resources formanufacturing in comparison to zinc-die casted products.

In contrast to material compositions that are highly loaded withfillers, the magnetic/ferromagnetic material of the present disclosureshows optimized mechanical properties, in particular dimensionalstability under heat and impact strength due to the improved meltviscosity and glass transition temperature.

The material of the present disclosure possesses the ability to adhereto other components/materials, e.g., substrates and resins, which isimportant for multicomponent injection molding, e.g. for molding handlescomprising two or three different materials.

The tooth cleaning elements of the oral care implement, e.g. bundle offilaments forming one or a plurality of tufts, may be attached to thehead by means of a hot tufting process. One method of manufacturing thehead with tufts of filaments embedded in the head may comprise thefollowing steps: In a first step, tufts are formed by providing adesired amount of filaments. In a second step, the tufts are placed intoa mold cavity so that ends of the filaments which are supposed to beattached to the head extend into said cavity. The opposite ends of thefilaments not extending into said cavity may be either end-rounded ornon-end-rounded. For example, the filaments may be not end-rounded incase the filaments are tapered filaments having a pointed tip. In athird step the head is formed around the ends of the filaments extendinginto the mold cavity by an injection molding process, thereby anchoringthe tufts in the head. Alternatively, the tufts may be anchored byforming a first part of the head—a so called “sealplate”—around the endsof the filaments extending into the mold cavity by an injection moldingprocess before the remaining part of the oral care implement is formed.Before starting the injection molding process the ends of the tuftsextending into the mold cavity may be optionally melted or fusion-bondedto join the filaments together in a fused mass or ball so that the fusedmasses or balls are located within the cavity. The tufts may be held inthe mold cavity by a mold bar having blind holes that correspond to thedesired position of the tufts on the finished head of the oral careimplement. In other words, the tufts attached to the head by means of ahot tufting process are not doubled over a middle portion along theirlength and are not mounted in the head by using an anchor/staple. Thetufts are mounted on the head by means of an anchor-free tuftingprocess.

Alternatively, the head for the oral care implement may be provided witha bristle carrier having at least one tuft hole, e.g. a blind-end bore.A tuft comprising a plurality of filaments may be fixed/anchored in saidtuft hole by a stapling process/anchor tufting method. This means, thatthe filaments of the tuft are bent/folded around an anchor, e.g. ananchor wire or anchor plate, for example made of metal, in asubstantially U-shaped manner. The filaments together with the anchorare pushed into the tuft hole so that the anchor penetrates intoopposing side walls of the tuft hole thereby anchoring/fixing/fasteningthe filaments to the bristle carrier. The anchor may be fixed inopposing side walls by positive and frictional engagement. In case thetuft hole is a blind-end bore, the anchor holds the filaments against abottom of the bore. In other words, the anchor may lie over the U-shapedbend in a substantially perpendicular manner Since the filaments of thetuft are bent around the anchor in a substantially U-shapedconfiguration, a first limb and a second limb of each filament extendfrom the bristle carrier in a filament direction. Filament types whichcan be used/are suitable for usage in a stapling process are also called“two-sided filaments”. Heads for oral care implements which aremanufactured by a stapling process can be provided in a relativelylow-cost and time-efficient manner.

The following is a non-limiting discussion of example embodiments oforal care implements and parts thereof in accordance with the presentdisclosure, where reference to the Figures is made.

FIG. 1 shows a manual oral care implement 10, in this specificembodiment a manual toothbrush 10. The manual toothbrush 10 comprises ahandle 12 to which a connector 14 is attached, and a brush head 16. Thebrush head 16 is repeatedly attachable to and detachable from the handle12 via connector 14.

FIGS. 2 to 5 show a schematic perspective view, a side view, a frontview and a top-down view of handle 12, respectively, handle 12comprising connector 14. The connector 14 comprises a firstsubstantially cylindrical section 18, a second substantially cylindricalsection 20, and an at least partially conically shaped section 22connecting the first and the second cylindrical sections 18, 20. Thefirst substantially cylindrical section 18, the at least partiallyconically section 22 and the second substantially cylindrical sections20 are arranged in consecutive order and define together a longitudinallength extension 24 of connector 14. The first substantially cylindricalsection 18 and the second substantially cylindrical section 20 areplaced off-center with respect to the longitudinal length extension 24of the connector 14. As derivable from side view of FIG. 7 , the firstand the second substantially cylindrical sections 18, 20 have a firstand a second longitudinal central axis 74, 76, respectively, which aredefined as the symmetry axis of the first and the second substantiallycylindrical sections 18, 20. The first and the second substantiallycylindrical sections 18, 20 may be placed/arranged with respect to eachother so that the second longitudinal central axis 76 of the secondcylindrical section 20 is located off-center with respect to the firstlongitudinal central axis 74 of the first cylindrical section 18 by adistance 78 of about 1 mm to about 2.5 mm, or of about 1.5 mm to about 2mm, or of about 1.65 mm. In other words, when seen in a side view (cf.FIGS. 3, 7 and 8 ), the central axis 76 of the second substantiallycylindrical section 20 is offset/eccentric from the longitudinal centralaxis 74 of the first substantially cylindrical section 18 by a distance78 of about 1 mm to about 2.5 mm, or of about 1.5 mm to about 2 mm, orof about 1.65 mm.

The handle 12 has a distal end 54 and a proximal end 56, the proximalend 56 being closest to a brush head 16 attachable to the handle 12. Asshown in FIGS. 8 to 10 , proximal end 56 of handle 12 comprising ahollow portion/recess 58 into which a portion of the first substantiallycylindrical section 18 is fixed, e.g. by a press-fitting process and/orgluing.

The proximal end 56 of the handle 12 comprises a chamfered surface 60.The cross-sectional area 62 extending substantially perpendicular to thelongitudinal length extension 64 and the chamfered surface 60 define anangle α from about 15° to about 30°, or from about 18° to about 28°, orabout 25°.

FIGS. 6 and 7 show a schematic front and side view of connector 14,respectively. The first substantially cylindrical section 18 and thesecond substantially cylindrical section 20 have each a length extension26, 28 and a cross-sectional area 30, 32 extending substantiallyperpendicular to the length extension 26, 28. The cross-sectional area30 of the first substantially cylindrical section 18 and the secondcross-sectional area 32 of the second substantially cylindrical section20 is substantially circular. The first substantially cylindricalsection 18 has a cross-sectional area 30 being greater than thecross-sectional area 32 of the second substantially cylindrical section20. The first cross-sectional area 30 has a diameter 36 of about 8 mm toabout 10 mm, or about 9 mm, while the second cross-sectional area 32 hasa diameter 34 of about 4 mm to about 6 mm, or about 5 mm.

The first substantially cylindrical section 18 comprises a flatteningportion 38 at the outer lateral surface 80 of connector 14. Flatteningportion 38 extends along the length extension 26 of the firstsubstantially cylindrical section 18. As further derivable from FIGS. 8to 10 , the flattening portion comprises a recess 40 which forms aninner cavity 82 within the connector 14. A spring-loaded ball element 42is inserted into cavity 82 and is fixed therein, e.g. by a press-fittingprocess and/or gluing. The spring-loaded ball element 42 is an elementwith a snap-fit locking mechanism to provide sufficiently strongconnection and stability between head 16 and handle 12 in an axialdirection, i.e. along the longitudinal length extension 24 of theconnector and oral care implement 10. The spring-loaded ball element 42comprises a ball 44 and a spring 46, the spring 46 applying a radialforce onto the ball 44 towards the outer circumference 48 and outerlateral surface 80 of connector 14. When the brush head 16 is attachedto the handle, ball 44 extends slightly beyond the outer lateral surfaceof the first substantially cylindrical section 18 and arrests in acorresponding recess 70 provided in a hollow portion (66) of the headshaft (cf. FIGS. 11 and 12 ). Both, the spring 46 and the ball 44 may bemade from stainless steel.

The first and the second substantially cylindrical sections 18, 20 havea first and a second outer lateral surface 50, 52, respectively, and thefirst and the second substantially cylindrical sections 18, 20 arearranged with respect to each other so that a part of the first outerlateral surface 50 and a part the second outer lateral surface 52 aresubstantially in straight alignment. The flattening portion 38 isarranged opposite the first and second outer surfaces 50, 52 beingsubstantially in straight alignment.

FIG. 11 shows a perspective view of brush head 16, and FIG. 12 arespective bottom view. Head 16 comprises hollow portion 66 forreceiving the second substantially cylindrical section 20, the at leastpartially conically shaped section 22 and a part of the firstsubstantially cylindrical section 18 of connector 14. Hollow portion 66has an inner wall 68 comprising recess 70 for receiving a portion ofball 44 of the spring-loaded ball element 42. Inner wall 68 of hollowportion 66 further comprises two ribs 72 being arranged opposite eachother for precisely adjusting the head 16 on the connector 14.

FIG. 13 shows a flow chart of the steps for manufacturing the handle 12comprising the connector 14 of the oral care implement 10 according tothe present disclosure: In step 1000 handle 12 with distal end 54 andproximal end 56 comprising hollow portion 58 is injection molded. A softcomponent forming a thumb rest 102 is injection molded over the handlematerial. In step 2000 handle 12 is covered with a metal coating 104 byelectroplating. In step 3000 at least a part of the connector 14 isinjection molded, the connector 14 having an outer lateral surface 80and a recess therein, and the recess forming a cavity 82 within theconnector 14. The connector may be injection molded from PBT, optionallycomprising about 30 weight % glass fibers. In step 4000 a spring-loadedball-snap element 42 is inserted and fixed in the cavity 82 of theconnector 14 by press-fitting. In step 5000 the connector 14 comprisingthe spring-loaded ball-snap element 42 is inserted into the hollowportion 58 at the proximal end 56 of the handle 12. The connector 14 isfixed in the hollow portion 58 by gluing, or alternatively by weldingand/or press-fitting. In step 6000 a ring 100, which may be made fromstainless steel is attached to the proximal end 56 of the handle 12 bypress-fitting and gluing. Optionally, a logo or indication element 106may be attached onto the surface at the distal end 54 of the handle 12,for example by applying a heat transfer foil, metal letters or a metalemblem.

In the context of this disclosure, the term “substantially” refers to anarrangement of elements or features that, while in theory would beexpected to exhibit exact correspondence or behavior, may, in practiceembody something slightly less than exact. As such, the term denotes thedegree by which a quantitative value, measurement or other relatedrepresentation may vary from a stated reference without resulting in achange in the basic function of the subject matter at issue.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

What is claimed is:
 1. A connector comprising: a first substantiallycylindrical section having a cavity with a spring-loaded ball-snapelement comprising a ball and a spring; a second substantiallycylindrical section; an at least partially conically shaped sectionconnecting the first and the second substantially cylindrical sections,the first and the second substantially cylindrical sections and the atleast partially conically section define a longitudinal length extensionwherein the first substantially cylindrical section and the secondsubstantially cylindrical section are off-center with respect to thelongitudinal length extension; and a head having a hollow portiondimensioned to receive the second substantially cylindrical section, theat least partially conically shaped section and a part of the firstsubstantially cylindrical section of connector, wherein the hollowportion has an inner wall with a circular recess dimensioned to receivethe ball, removably attaching the head to the second substantiallycylindrical section.
 2. The connector of claim 1, wherein the firstsubstantially cylindrical section has a cross-sectional area that isgreater than the cross-sectional area of the second substantiallycylindrical section.
 3. The connector of claim 1 further comprising ahandle having a proximal end defining a hollow portion dimensioned toreceive a portion of the first substantially cylindrical section.
 4. Theconnector of claim 3 wherein, the portion of the first substantiallycylindrical section is press fit into the hollow portion of the handle.5. The connector of claim 3 further comprising a cross-sectional areaextending substantially perpendicular to the longitudinal lengthextension, wherein a chamfered surface of the proximal end of the handleand the cross-sectional area define an angle from 15° to 30°.
 6. Thehandle of claim 5, wherein the angle is 18° to 28°.
 7. The connector ofclaim 1, wherein the first substantially cylindrical section comprises aflattening portion.
 8. The connector of claim 7, wherein the recess withthe spring-loaded ball element is provided at the flattening portion. 9.The connector of claim 1, wherein an inner wall of the hollow portion ofthe head further comprises two ribs arranged opposite each other, foradjusting the head on the connector.
 10. The connector of claim 2,wherein the first cross-sectional area has a diameter of 8 mm to 10 mmand the second cross-sectional area has a diameter of 4 mm to 6 mm. 11.The connector of claim 1, wherein the first substantially cylindricalsection comprises a flattening portion with a recess which forms thecavity.